Functional properties and biological activities of plant-derived polyphenolic compounds have gained great interest due to their epidemiologically proven health benefits and diverse industrial applications in the food and pharmaceutical industry. Moreover, the food processing conditions and certain chemical reactions such as pigmentation, acylation, hydroxylation, and glycosylation can also cause alteration in the stability, antioxidant activity, and structural characteristics of the polyphenolic compounds. Since the (poly)phenols are highly reactive, to overcome these problems, the formulation of a complex of polyphenolic compounds with natural biopolymers is an effective approach. Besides, to increase the bioavailability and bioaccessibility of polyphenolic compounds, milk proteins such as whey protein concentrate, sodium caseinate, and milk protein concentrate act as natural vehicles, due to their specific structural and functional properties with high nutritional value. Therefore, milk proteins are suitable for the delivery of polyphenols to parts of the gastrointestinal tract. Therefore, this review reports on types of (poly)phenols, methods for the analysis of binding interactions between (poly)phenols–milk proteins, and structural changes that occur during the interaction.

Stevia rebaudiana is a natural sweetener herb that is increasingly used in herbal medicines in the food and cosmetics industries. Molecular methods can be combined with morphological techniques to identify stevia genotypes as a starting material to produce more reliable bioproducts. This study evaluated the level of the genetic and biochemical diversity in various stevia genotypes using HPLC (high performance liquid chromatography) analysis and random amplified polymorphic DNA (RAPD) markers. Stevia genotypes collected from different locations of the world showed clear variations at the biochemical and genetic level in Polish climate conditions. The influence of the genotypes on the content of steviol glycosides, antioxidants, phenols, flavonoids, and tannins was analyzed using phytochemical assays. Genotypes from Morocco, Poland, Egypt, and Nigeria can be defined as samples of higher quality compared to other genotypes analyzed in terms of the amount of steviol glycosides. Considering the rebaudioside A/stevioside ratio as a selection criterion, genotypes from Australia, China, India, and Pakistan should be considered to be valuable in terms of suitability for obtaining new varieties. The present results of RAPD marker analysis indicated differential banding pattern and considerable polymorphism among all ten stevia genotypes. Genotypes from Morocco, Egypt, Poland, Nigeria, China, and India, as genetically different, can be selected for further stevia breeding programs.

The phytochemical characteristic analysis of a group of 30 haskap berry genotypes was carried out bearing in mind the concern for the consumption of food with high nutraceutical value that helps maintain good health. Phytochemical fruit composition and antioxidant activity were assessed by the Folin–Ciocalteau, spectrophotometric, DPPH (1,1-diphenyl-2-picrylhydrazyl) as well as ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) method. Evaluation of antioxidant activity was referred to as the Trolox equivalent. The observed differences in the content of phenolics, flavonoids, vitamin C and antioxidant activity allowed us to select genotypes which, due to the high level of the analyzed compounds, are particularly recommended in everyone’s diet. In addition, the analysis of the prospects of increasing the analyzed phytochemical properties, estimated by parameters such as heritability and genetic progress, indicates the effectiveness of breeding in relation to each of the analyzed traits. The results of the presented research can be used in the implementation of future breeding programs for this valuable species.

Stevia (Stevia rebaudiana Bertoni) is an essential herbal plant used as a sweetener. The demand for stevia is growing due to its low caloric and medicinal value, hence the need for a more thorough investigation of its nutritional and biological properties. Nanoparticles of metal oxides have been found to have broad applications in agriculture for the stimulation of plant growth and development. The study aimed to assess the effect of various zinc oxide nanoparticles (ZnONPs) concentrations on stevia plants’ quantitative and qualitative traits obtained in in vitro cultures. Micropropagation of two stevia varieties, Candy and Morita, was carried out using explants of shoot tips placed on MS medium supplemented with 1.0 mg dm–3 BA and 0.1 mg dm–3 IBA and with ZnONPs at concentrations of 0 (control), 10, 20, 30 and 40 mg dm–3. The obtained results indicated that high concentrations of ZnONPs stimulated the propagation of shoots. On the other hand, they negatively influenced shoot length, root number and length, and the fresh weight of the plantlets. The presence of zinc oxide nanoparticles in the medium increased the potassium, calcium, magnesium, and zinc content while decreasing the sodium and iron content in the regenerated stevia plantlets. The total phenolic content in the Candy variety was higher in the treatments with ZnONPs than in the control plants, while it was varied in the Morita variety. In both varieties, total antioxidant content measured by the ABTS method showed significantly higher in the treatments with 20–30 mg dm–3 ZnONPs than in the control. The content of chlorophyll a, chlorophyll b and chlorophyll a + b in the Morita variety was higher in the treatments with 10 and 20 mg dm–3 ZnONPs than in the control. On the other hand, high concentrations of ZnONPs negatively affected the content of carotenoids in both varieties. The study showed that stevia plants obtained in in vitro cultures on control media and media containing ZnONPs had a high content of valuable minerals, phytocompounds with antioxidant properties, and photosynthetic pigments.

The in vitro culture technique can be used for micropropagation of medicinal plants as well as for creating genotypes with an improved profile of phytochemical compounds. For this purpose, somaclonal variability may be used for the induction of genetic diversity among regenerants. The paper presents a protocol for obtaining Scutellaria baicalensis regenerants by indirect organogenesis and the assessment of their genetic variability with the use of start codon-targeted markers. The most intense process of indirect shoot organogenesis was observed on Murashige and Skoog medium supplemented with kinetin and 6-Benzylaminopurine (0.5 mg × dm⁻³ each)—7.4 shoot per explant on average. The callogenesis process occurred on the medium supplemented with TDZ, while the medium supplemented with GA₃ allowed for direct shoot organogenesis and was used for the micropropagation of regenerants. In the analysis of plantlets obtained by indirect organogenesis, 11 ScoT markers generated a total of 130 amplicons, 45 of which were polymorphic. This analysis showed genetic diversity of regenerants in relation to the donor plant as well as within them, with mean similarity among the analyzed genotypes at the level of 0.90. This study confirms that the use of in vitro cultures allows for the possibility to generate genetic variability in Scutellaria baicalensis, which can be effectively revealed with the use of the SCoT marker.

The efficiency and method of regeneration in in vitro culture conditions depend primarily on the plant growth regulators (PGRs) used. Even growth regulators belonging to one group may have different effects, stimulating the process of direct or indirect organogenesis, thus possibly disturbing the genetic stability among regenerants. The main aim of this study was to identify the genetic stability of Scutellaria baicalensis regenerates obtained by in vitro culture method using start codon targeted (ScoT) markers. S. baicalensis nodal explants were regenerated on MS medium supplemented with kinetin (KIN) at concentrations of 0.25, 0.5, 1.0, and 2.0 mg × dm⁻³ or benzylaminopurine (BAP)—0.25, 0.5, 1.0, and 2.0 mg × dm⁻³. The effects of the number of propagated shoots, length, number of nodes, and fresh mass of regenerants were assessed. Moreover, the genetic stability of the regenerants was analyzed using start codon targeted (SCoT) markers. Direct shoot organogenesis was observed on an MS medium containing kinetin, while indirect shoot induction occurred on an MS medium supplemented with BAP. The highest average number of shoots (3.6) was achieved for the MS + KIN medium at a concentration of 0.25 and 5.8 for the MS + BAP 1.0 medium. The average length and average number of nodes were the highest on the MS + BAP 0.25 medium (50.0 and 6.0, respectively), while the lowest values of these features were observed on the MS + KIN 2.0 medium (40.3 and 4.9, respectively). A total of 111 amplified bands were exhibited by SCoT primers. Three of the analyzed primers revealed four unique genotype-specific markers. The average percentage of polymorphism obtained was 36.7%. The analysis of genetic similarity revealed a high level of genetic similarity between the donor plant and regenerants obtained on MS “0” (medium without the addition of phytohormones). A slightly lower value of genetic similarity was observed for regenerants obtained by direct organogenesis (MS + KIN medium at all concentrations). Indirect shoot organogenesis observed on the MS + BAP medium (all concentrations) resulted in the highest differentiation, both in relation to the donor plant and MS “0” regenerants. The results of our work indicate that, in the case of S. baicalensis, the maintenance of genetic stability depends primarily on the presence of the cytokinin type in the medium.